How to prevent accidentally dragging vertex on selection?
Sounds like you are using the select mode &quot;tweak&quot; which has that behavior that you are describing, where you can click and drag the mesh, but you really want something that is more akin to the &quot;box select&quot; where you are just selecting, and not moving. You can click individual vertices in box select mode as well. The top left of the 3d viewport shows your select mode, and W cycles through them.
&quot;tweak&quot; select mode

&quot;box&quot; select mode

https://docs.blender.org/manual/en/latest/interface/selecting.html#tool-select-box